Lexmark International, Inc.

Graydon Randall Dodson

Adam Jude Ahne

Roger Steven Cannon

Gary Allen Denton

Keith Bryan Hardin

Christopher Alan Adkins

James Ronald Booth

Matthew David Clarke

Joshua Scott Potter

Ellis Matthew King

A toner cartridge for an image forming device includes a body for holding toner and a flight. The flight contains magnetic particles and is configured to guide movement of a magnetic field sensor. The magnetic particles generate a magnetic field that the sensor reads. Other systems and methods are disclosed.

Toner cartridge for image forming device including flight with magnetic particles to generate a magnetic field

Magnetic keys having a plurality of magnetic plates are disclosed. The location and orientation of the magnetic plates are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Magnetic keys having a plurality of magnetic plates

Magnetic keys having a plurality of magnetic layers having holes are disclosed. The location and orientation of the holes are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Magnetic keys having a plurality of magnet layers with holes

Methods for authenticating printer supply items using revocation lists are disclosed. Revocation lists are updated using DNSSEC to communicate between a printer and a DNS name server. A first domain name is created containing a request for a challenge to an authentication module and sent to the DNS name server. A second domain name is created containing a response to the challenge and sent to the DNS name server. The DNS name server indicates success or failure, which is used to authenticate the printer supply item. Other systems and methods are disclosed.

Systems and methods for authentication of printer supply items

Systems and methods for authenticating printer supply items using revocation lists are disclosed. Revocation lists are updated using DNSSEC to communicate between a printer and a DNS name server. A domain name is created containing a printer supply item serial number, a message digest, and a message authentication code. The domain name is sent to the DNS name server, and the returned IP address is used to update a revocation list. Other systems and methods are disclosed.

A helical physical unclonable function is disclosed. The helical physical unclonable function may be used to authenticate a supply item for an imaging device. Measurements of the magnetic field adjacent a helical flight are stored in a non-volatile memory to be used by an imaging device to authenticate the supply item. Other systems and methods are disclosed.

Magnetic helical physical unclonable function measured adjacent to flight

A helical physical unclonable function is disclosed. The helical physical unclonable function may be used to authenticate a supply item for an imaging device. Measurements of the magnetic field above a helical flight are stored in a non-volatile memory to be used by an imaging device to authenticate the supply item. Other systems and methods are disclosed.

Growing community of inventors

Lexington, KY, United States of America

Graydon Randall Dodson